decrypt

This method will decrypt the provided string. If null is passed into this
method it should noop and return null. No exceptions should ever escape
from this method.
Note: Currently method is ONLY called to decrypt
openjpa.ConnectionPassword and openjpa.Connection2Password properties.

encrypt

This method will encrypt the provided string. If null is passed into this
method it should noop and return null. No exceptions should ever escape
from this method.
NOTE : This method is not called by the OpenJPA runtime. It is here for
possible future uses.